What is belching? Belching, or burping, is the expulsion of gas from the esophagus and stomach out through the mouth. As the gas escapes, it produces the characteristic sound known as a burp or belch (eructation). The most common cause of belching is swallowing air. Swallowing air and belching are natural occurrences that result from eating or drinking too quickly. Chewing gum or drinking carbonated beverages can also introduce air into the stomach and cause belching. Because infants frequently swallow air when feeding, burping or belching is normal after they have been fed. The act of burping an infant helps relieve the discomfort caused by swallowed air. In addition to swallowed air, many different types of gastrointestinal conditions and diseases can cause belching. Belching may occur with conditions that slow digestion, such as gastroparesis (delayed stomach emptying), and mechanical obstructions, such as pyloric obstruction (a blockage between the stomach and small intestine). Pregnant women may also experience belching due to hormonal changes that slow the digestive process. Belching can also arise from conditions that impair the normal digestive process in other ways, such as acid reflux, hiatal hernia, or stomach acid deficiency. In these cases, belching may occur frequently after meals, and it may become chronic. Belching is rarely associated with a medical emergency. Seek immediate medical care (call 911) if your belching is associated with severe abdominal pain, chest pain, persistent nausea and vomiting, or high fever. If your belching is persistent or causes you concern, seek prompt medical care.